Parse optional and named parameters.

pkg/front_end/lib/src/fasta/parser/listener.dart

Index: pkg/front_end/lib/src/fasta/parser/listener.dart
diff --git a/pkg/front_end/lib/src/fasta/parser/listener.dart b/pkg/front_end/lib/src/fasta/parser/listener.dart
index 5a400b94e4a5d7804b90b70da31aa87dd313f445..149d2bd80fc9696dee148a3eca06d96be13775db 100644
--- a/pkg/front_end/lib/src/fasta/parser/listener.dart
+++ b/pkg/front_end/lib/src/fasta/parser/listener.dart
@@ -9,6 +9,7 @@ import '../scanner/token.dart' show BeginGroupToken, Token;
 import '../util/link.dart' show Link;
 
 import 'error_kind.dart' show ErrorKind;
+import 'parser.dart' show FormalParameterType;
 
 /// A parser event listener that does nothing except throw exceptions
 /// on parser errors.
@@ -152,7 +153,7 @@ class Listener {
 
   void beginFormalParameter(Token token) {}
 
-  void endFormalParameter(Token thisKeyword) {
+  void endFormalParameter(Token thisKeyword, FormalParameterType kind) {
     logEvent("FormalParameter");
   }
 
@@ -871,6 +872,10 @@ class Listener {
     logEvent("ValuedFormalParameter");
   }
 
+  void handleFormalParameterWithoutValue(Token token) {
+    logEvent("FormalParameterWithoutValue");
+  }
+
   void handleVoidKeyword(Token token) {
     logEvent("VoidKeyword");
   }